[WARNING: This post contains words which some readers may find offensive. I use them only to explain a point about offensive language, but please don’t read on if you may be upset by reading racial-, sexuality- or health-related slurs.]
I don’t consider myself to be a Grammar Nazi: I like to think I embrace change and acknowledge the part different cultures have to play in language. However, those of us who stand up for correct usage are often called by that name. And the use of the word Nazi offends some, not just because of the implied criticism of defending good grammar, but because using it in this context is considered to be trivialising the acts of the real Nazis, back in 20th century Europe.
I can see the point. I can. And I try not to use extreme language like “grammar Nazi” where possible.
But the problem is, the English language is peppered with words and phrases that, taken literally, are extreme, and therefore have become trivialised by exaggerated usage. Here are just a few examples:
“I’m starving!”
“My back’s killing me today!”
“It’s driving me crazy”
“It’s hell out there.”
“She had a fit, because I got there late.”
Political correctness can definitely take things too far. The word “brainstorm” achieved notoriety a while back when people decided it might offend epilepsy suffers, for example. I don’t suffer from epilepsy, so perhaps I’m not qualified to comment, but in my view, since brainstorming is not derived from anything to do with epilepsy and doesn’t have negative connotations, I think this was a step too far. A survey of epilepsy patients at the time suggested they didn’t care either.
There are some words that most people tend to be uncomfortable about, though. These fall into two main categories. The first is made up of words that are used as insults and are clearly derived from a disadvantaged (or previously disadvantaged) sector of society. This category would include words such as “Spaz” (based on the old word for cerebral palsy sufferers), “Gay” (as an insult, usually for behaviour not related to sexuality), and of course racial slurs.
The second category contains words which have extreme and upsetting meanings, and which we feel uncomfortable trivialising by overuse. Holocaust, genocide and massacre for example. Nazi falls into this second category. But it’s a smaller category than the first and harder to contain. Most of us don’t baulk at talking about “car crash TV” or “terrorising” a neighbourhood.
It’s a balance – exaggerations will always be a part of our language, and using them to shock means we need increasingly shocking words to use. But on the other hand, very few of us want to offend or upset, and I think it’s worth just pausing to consider our audience when we use language which might, inadvertently, do so.
elmowrites 
Very good points, I agree entirely.
Recently at work I’ve caught myself almost using the word “spaz” without even thinking. We used it as youngsters – we didn’t know. Our nickname for one of the other kids was “homo” – we had no idea.
Fortunately with the written word, we tend to proof-read and second-guess ourselves so it’s far easier to rip this sort of thing out before releasing it to a wider audience.
It’s so easy to use these words casually, especially when we grew up with them in the playground and didn’t realize what they meant or implied until they were firmly entrenched in our vocabulary. Editing definitely makes it easier – I sometimes which I had a backspace key on my mouth!